1. Technical Field of the Invention
The present invention comprises a method for assembling a reciprocating compressor for use in an air conditioning unit and a reciprocating compressor obtained by the method.
2. Description of the Prior Art
Reciprocating compressors are well known in the prior art. A conventional compressor comprises a piston slidably telescoped into a cylinder. The internal volume of the cylinder is divided into two chambers by the piston: a suction chamber and a compression chamber. The suction and compression chambers are connected by suction ports that perforate the piston. The suction ports are opened and closed by a plate-shaped suction valve mounted on the piston. The suction valve is opened at the suction stroke of the piston, during which gas or fluid is sucked from the suction chamber into the compression chamber. The suction valve is closed at the compression stroke of the piston, during which gas or fluid in the compression chamber is compressed.
In such a reciprocating compressor it is desirable to improve the volumetric efficiency of the cylinder and to eliminate any irregular performance of the compressor. The volumetric efficiency of the cylinder can be improved by minimizing the volume of the compression chamber when the piston is disposed at the top of its stroke. Irregular performance of the compressor can be eliminated by ensuring that the minimum volume of the compression chamber of each compressor is constant.
A drawback of conventional compressors is that the minimum volume of the compression chamber is not constant from one compressor to the next. The cylinder, piston and other components are generally machined to within a specified tolerance. When the effect of the tolerances of all of the components are added together, the differences in chamber volume can be significant. Even slight differences in chamber volume could result in irregular performances by the respective compressors.
Of course, consistent performance is preferred because the rest of the air conditioning unit is designed to cooperate with a compressor having a specified performance. Any variation from this specified performance will adversely affect the unit as a whole. Thus, to prevent such variation in the chamber volume, the solution commonly employed is to machine the respective components to extremely high accuracy (i.e., low tolerance). Such precise machining increases the cost of manufacturing the compressor.
Another disadvantage of conventional compressors is that, although the seat surface of a suction valve can be accurately machined, the seat surface is frequently damaged during handling of the piston. For example, during assembly of the compressor, the seat surface might collide with another component, thereby causing the seat surface to be scratched. The result of having a seat surface with an imperfection is that the performance of the suction valve is adversely affected so as to lower the compression ratio.